Re: [PATCH] libnvdimm: remove redundant assignment to pointer 'dev'

From: Dan Williams
Date: Mon Feb 05 2018 - 13:44:24 EST


On Mon, Feb 5, 2018 at 10:20 AM, Ross Zwisler
<ross.zwisler@xxxxxxxxxxxxxxx> wrote:
> On Mon, Feb 05, 2018 at 02:08:52PM +0000, Colin King wrote:
>> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>>
>> Pointer dev is being assigned a value that is never read, it is being
>> re-assigned the same value later on, hence the initialization is redundant
>> and can be removed.
>>
>> Cleans up clang warning:
>> drivers/nvdimm/pfn_devs.c:307:17: warning: Value stored to 'dev' during
>> its initialization is never read
>>
>> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> Reviewed-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
>
> More importantly this fixes a potential NULL pointer dereference. nd_pfn
> is checked for NULL a few lines down, but we would have crashed here trying to
> get nd_pfn->dev.
>

No we wouldn't crash. We're just calculating the address, not
de-referencing a NULL pointer.